(compilation-start): Move `erase-buffer' up

before selecting the desired mode to not spend time fontifying
old contents.

1 files changed, 3 insertions, 2 deletions

diff --git a/lisp/progmodes/compile.el b/lisp/progmodes/compile.el
index a27a5282b42..e0c8ded307a 100644
--- a/lisp/progmodes/compile.el
+++ b/lisp/progmodes/compile.el
@@ -935,6 +935,7 @@ Returns the compilation buffer created."
                     (substitute-env-vars (match-string 1 command))
                   "~")
               default-directory))
+        (erase-buffer)
         ;; Select the desired mode.
         (if (not (eq mode t))
             (funcall mode)
@@ -944,11 +945,11 @@ Returns the compilation buffer created."
         (if highlight-regexp
             (set (make-local-variable 'compilation-highlight-regexp)
                  highlight-regexp))
-        (erase-buffer)
         ;; Output a mode setter, for saving and later reloading this buffer.
         (insert "-*- mode: " name-of-mode
                 "; default-directory: " (prin1-to-string default-directory)
-                " -*-\n" command "\n")  (setq thisdir default-directory))
+                " -*-\n" command "\n")
+        (setq thisdir default-directory))
       (set-buffer-modified-p nil))
     ;; If we're already in the compilation buffer, go to the end
     ;; of the buffer, so point will track the compilation output.